Dynamo-electric machine



(No Model.) 3 Sheets-Sheet 1'. R. M. HUNTER.

DYNAMO ELECTRIC MACHINE.

Patented Feb 12, 1889.

\p O O o o mfi Q gi n g m w No Mbdel.) v 3 Sheets-Sheet 2. R. M. HUNTER.

DYNAMO ELECTRIC MACHINE.

No. 397,550. Patented Feb. 12, 1889.

(No Model.)

. 3 Sheets-Sheet 3. R. M. HUNTER.

DYNAMO ELECTRIC MACHINE.

No. 397,550. Patented Feb. 12, 1889.

u. PETERS, fimloiilfmgnpher, Wanbungicn. n. c,

UNITED STATES PATENT RUDOLPH M. HUN'IER, OF PHILADELPHIA, PENNSYLVANIA.

DYNAMIC-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 397,550, dated February 12, 1889. Application filed July 14, 1888. Serial No. 279,942. (No modehl T0 (LZZ whom it may concern:

Be it known that l, RUDOLPH M. HUNTER, of the city and county of Philadelphia, and State of Pennsylvania, have invented an Improvement in Dynamo-Electric Machines and Motors, (Case (33,) of which the following is a specification.

My invention has reference to dynamo-electric machines and motors; and it consists of certain improvements fully set forth in the following specification and shown in the accompanying drawings, which form part thereof.

Much loss has been experienced from use of dead wire on the armatures of dynamo-electric machines and motors, and this is so not only in ring or Gramme armatures, but exists also in the drum or Siemens armature. Many ways have been devised to lessen the effect of the useless and objectionable resistance of this dead wire in the armature, and particularly so infthe' case of the Gramme ring. '1 It has been clearly proved that in the Gramme ring when the iron core was not saturated the wire on the inside of the ring was absolutely No current is generated in it, and its function is simply as a conductor. \Yhen the low resistance of the armature is of importance, it is perceived that the dead wire is considerable of an objection. Yhen the core of the armature is fully saturated and the magnetic lines of force pass through it to find their way to the opposite pole of the machine, the induction effect on the moving wire is such that it produces a current in the inside wire in the reverse direction to that produced in the outer coils by. the field-magnets. This reverse current reduces the efficiency of the machine, and is therefore very objectionable.

My invention, so far as the armatureis concerned, relates to the Gramme ring and is directed to improve'the efiicieney of the machine by utilizing the wire upon the internal surface of the armature-ring. It has been proposed to revolve a lrramme armature-ring on the poles of the field-magnets, so that the annular ring formed by the armature fits into curved grooves in the north and south polepieces of the field-magnets. This arrangement, however, has much objection in its mechanical constructions and necessitates the l l l i in practice from and also because i 1 1 l t l l 1 one commutator. screened and acted simply as a resistance.

l l i l i l l l I l v i and south poles of the employment of a very short armature. It has also been proposed to support a field-magnet within the armature and allow it to remain stationary by action of gravity while the armature revolved; but this is very objectionable a mechanical point of view, the looseness of the support of the internal field-magnets would render the magnetic condition of the armature unstable and necessitate constant watching of the brushes at the commutator.

In carrying out myinvention, so far as it relates to the armature, I construct my armature like an ordinary Gramine ring, only I make it long, and inside of this I place a second ring with coils to form an internal field, and this latter ring may be wound like a Gramme or a drum armature. Both of these rings are secured to the same frame and revolve together as an integral piece of apparatus. The external field maybe of any construction. I may connect the armature and internal field-coils in series or parallel, the latter being the simplest and requiring only The coils on the armature and internal field are the same in number and are connected to the same commutator-sections, only the coupling up of the internal field is such as to bring its north and south poles at right angles to the north armature, or thereabout, and so as to correspond with the fixed external poles. The operation is such that as the armature and internal field-coils rotate their poles shift also, and the internal iield magnetizes the internal wire of the armature and greatly increases its inductive effect, and enables heavier cores to be used. This is particularly advantageous in motors, where with a small motor we can obtain a large torque at slow speed. The field-magnets may be wound with coils suitable for a series machine or shunt or compound machine. It is evident that by winding a series coil on the external field and in series with the armature and internal field, and with an external long shunt coil around both the internal field, armature, and series field-coil, a very sensitive selfgovernin g motor may be made by properly proportioning the resistances. It is essentially the combination of the windings of long and short shunt machines, and the law of winding is peculiar and different from that of any other machine. The internal field and the stationary shunt-coils of the external field may be parallel and both in rotation with the armature as short shunts. There are many modifications to the windingof this machine.

The field-magnets I form of horseshoe shape and in sections to reduce as far possible heating and losses due to Foucault currents. These sections I prefer to make of good malleable iron or cast-steel, and the two opposing horseshoe-magnets are brought face to face with the only dividing lines through them in the center of the north where such breaks are not injurious. metal is continuous from pole to pole, and no joints or yoke-pieces are used at all. sections of these field-magnets are bolted together and to standards at each end of nonmagnetic material in which the armatureshatt is supported by suitable bearings. These sections have lateral contact-pieces which hold them apart and form ventilating-spaces or passage-Ways between them, not only at the polar-extensions, but also at the cores. In the winding of the field-magnets I prefer to interpose a winding of iron or steel wire on top of a coil of insulated copper wire and under another coil of the latter to increase the strength of the field. The armature and internal field-coils I may also wrap in this manner with soft and well-annealed iron wire, forming an iron shell upon the outside or inside, or both, of the armature.

There are many other features of const ruction, more fully set out hereinafter, which are not so important as those above referred to.

In the drawings, Figure 1 is a plan view of a dynamo-electric machine or motor embodying my invention with the coils removed. Fig. 2' is an end View of same. Fig. 3 is a crosssection of same on line y y. Fig. t is a longitudinal sectional elevation of same on line m. Fig. 5 is a sectional elevation of a portion of the armature and internal field-magnets with the coils. Fig. 6 is a cross-sectional elevation of same on line 2 z, with part of the coils removed. Fig. '7 is an elevation of the armature removed. Fig. 8 is an end elevation (with part in section) of the external fieldinagnets. Fig. 9 is a perspective view showing two sections of the field-magnet. Fig. 10 is a sectional view of a portion of the brushholder. Fig. 1]. is a cross-section of same at its support concentric with the armatureshaft. Fig. 12 is a diagram illustrating one method of coupling up the coils of the armature and internal field in parallel. Fig. 13 is an illustrative drawing showing the connection of the external and internal fields in series with the armature. Figs. 14 and 15 are diagrams showing how the coils of the motor may be'coupled up with a variable field-resistance. Fig. 16 is a diagram illustrating my preferred winding for shunt-wound motor employing a series coil and long and short and south poles and The The l l i l i l l l l l l l J i i l l l l i l I l shunt field-coils. Fig. 17 is a perspective view of one of the core-segments for the armature and internal field, and Fig. 18 is a diagram showing a modifiedv winding of my machine.

A A represent two horseshoe field-magnets having their polar extensions brought end to end, (see Figs. 3 and 8,) and each of these horseshoeanagnets is preferably made up of sections A and A having bearings or dis tance projections a a, which hold said parts sutficiently separated, as at C, to allow free passage of air through both the core and polar extensions and yet allow them to be bolted firmly together to constitute a single structure. It will be noticed that the only break in the continuity of the magnetic metal or belt of the field is directly in the center of the polar-pieces and where it is not obj eetionable. The metal at these adjoining places is recessed, as at a and when the sections of the core are put together such recessed port-ions form the ventilatingapertures c, which are continuations of the ventilatingspaces C between the sections A A*.

D D are two end standards having feet and formed of brass, gun-metal, or other non-magnetie material, and these standards are bolted to the two horseshoe-cores A A by means of the four bolts B, and with distance-pieces 5 between them and the cores. This holds the cores firmly in position and makes the entire structure as solid as if east integral, and at the same time keeps the parts so separated that free ventilation and access can be had. The horseshoe-cores have the sections A different from the outside or end sections, A which are made to enlarge at the polar extensions to form a larger armature-space and allow of an armature of considerable length.

The field-coils are wound aboutthe vertical parts of the cores, and are kept in place by the brackets or flanges 0, of brass, bolted to the outer parts of the cores. They are made of brass or non-magnetic material to prevent the dissipation of the magnetic lines of force.

It is evident that while I prefer to make the sections of my external field-magnets of 1nalleable iron, they may be made of wroughtiron forged or when rendered fiuid with aluminium, or they may be of cast-iron. Broadly considered, these horseshoe-shaped magnets may be of solid wrought-iron not in sections; but I prefer to make them as shown.

I) and D are end bearings for the armature-shaft E and are secured to the standards D, as shown. The bearing D is supported away from the standard, so as to form the commutator-space. The inner and adjacent parts of the field-cores are curved, as at A to form the circle for the armature. (See Figs. 3, 8, and 9.)

The constructions of the armature and in ternal field are clearly shownin Figs. 3, 4, 5, (3, 7, 12, and 17. Secured upon the armatureshalt at each end of the field-pieces are the armature-frames F, of brass. Connecting these two frames are rods f and f, upon which are IIO r in position in the stationary field-magnet, the 1 the internal field is in shunt relation to the the core-rings L and K, (see Figs. 6 and 17,) forming two concentric rings, each formed of thin quarter-sections of thoroughly-annealed iron. These sections are stamped out to make them uniform, and are preferably without polar projections, so as to give more available space for wire. The outer ring, K, is much heavier than the internal ring, L, which latter is the core of the internal field. The two rings so formed are wound with coils of wire, preterably of the same number of coils, but with different numbers of turns, as the ampere turns or windings Z on the core L, when in shunt relation to the armature-coils to, will be very different and dependent upon the resistance necessary. It the commutator G has forty-eight sections, then there are fortyeight coils or sections of coils k, and also forty-eight coils l, and these are coupled up 1 in parallel, as shown in Fig. 12that is to i say, the armature-coils 7i and field-coils Z are so connected as to cause the north and south i poles of the field-magnets to be at right anglcs or substantially at right angles to the similar poles of the armature. \Yhen such armature and internal field magnets are hung internal field-poles will correspond with the external field-poles.

Another point which it is well to refer to is i that the generating capacity of the armature 3 is depcn den t upon the speed of its wire through the field, and for a given wire on the armature and speed of travel through the field the l strength of the field must be predetermined. Now the wire on the interior of the armature would have a much less speed than that upon the outside, and consequently the internal i field must be so wound as to produce in the internal wire'the same current as produced in the external wire.

If desired, the internal'field-coils and armature-coils may be each wrapped with a coveri ing' magnetic wire-such as indicated at m M-of well-annealed soft iron; but, if desired,

ither or both of such wrappings may be dispensed with.

I G is the commutator, and may be made in any way desired. In the construction in which armaturecoils each section of the commutator is coupled to one coil of the armature and one coil of the internal field, as shown in Figs. 12 and 16, which brings the poles of the said armature and internal field at right angles 1 with each other.

In the modification shown in Fig. 13 we have the two fieldcoils and armature in series employing two commutators, G and G, (the armature K and internal field, L, being sepa- 3 rated for clearness.) The brushes g are held in a suitable spring-clamp, I, so as to press i upon the commutator. These clamps are carried upon an adjustable arm, II, journaled on a boss, N, concentric wit-1 the armature-shaft l E and having an annular groove, 11. Carried by the arm H is an adjusting-handle, J, which any suitable manner.

, ance.

has its end screw-threaded, and is adapted to be turned to enter the annular groove 01 and hold. the arm II in any desired position to which it may be adjusted. The arm II has one of the brushes positively fixed to it at one end, and its other end has a slot, h, in which the other brush is adjustably secured. This will admit of sufficient adjustment of the brushes relatively to each other, and the adj ustability of the arm 11 by handle J will permit of the simultaneous adjustment of both brushes. These parts are shown in Figs. 1, 2, 4, 10, and 11.

The external field-coils may be wound in As shown, I have two sets of coils, P and I". In Figs. 8, 1t, and 15 these coils are shown as of the same resistance and coupled up in Fig. 14 for series and in Fig. 15 for parallel to vary the field resist- In addition to this there is shown he- 1 tween these coils a third coil, p, of iron or steel wire, which may be insulated or not, as

desired, to increase the field strengtln'and the 1 current may be shunted through these coils f for an instant at starting to produce a reactive or inductive action to quickly start the machine. Q is a switch in the circuit "1' for cutting these coils p out of circuit. There is i one of the coils p on each magnet, and these may be coupled in series, Fig. 11, or parallel, Fig. 15, the former being preferred.

In Figs. 14: and 15, S and 5 represent the 1 terminals of the machine, and R the motorcircuit or the connections on the machine between the coils.

ieterring now to Fig. 113, we have the armature constructed as before; but in this case the coils P are made shunt-coils of high rej sistance in a sluint-circuit, R, around the terminals of the machine constituting a long shunt, whereas the coils P are of low resistance and in series with the arnniture.

Itwill thus be seen that in this construction we have a compound machine combined with the internal field shuntcoil of the short-shunt type, forming a shunt only to the armature. In Fig. 18 we have the same winding with the exception that the external field long shunt is converted into a short shunt.

It is evident that the coils 7 may be used with the winding shown in Figs. 1 t3 and 11s, if desired. This machine is equally adapted as a generator or motor. For traction purposes the motor should be wound as a series machine; but for stationary work on constant potent ial circuits it is best as a double shunt self to the details, as they may be modified in various ways without departing from the spirit of my invention.

Having now described my invention, what -I claim as-new, and desire to secure by Letters Patent, is-

IIO

the combination of stationary field-magnets,

a rotating armature, internal field-magnets located and secured within the armature, so as to rotate therewith, and connections between the coils of the armature and internal field-coils, whereby they are coupled in par- 5 chine, having bearings for the shaft, and bolts for uniting the external field-magnets to the allel.

at. I11 a dynamo-electric machine or motor, the combination of a shaft, an armature secured to said shaft, concentric supplemental field-magnets also secured to said shaft and having a fixed mechanical relation with re spect to the armature, and electrical connections between the coils of the armature and field-magnets.

5. The combination of a shaft, an armature secured to said shaft, concentric field-magnets connecting-circuits between the commutatorsections, armature, and said field-coils, whereby the poles of the field-magnet shall be at right angles or substantially at right angles to the poles of the armature.

7. The combination of stationary field-magnets, a rotating armature, and rotating fieldmagnets concentric with said armature, connecting-circuits, and a commutator for changing the poles of the rotating field-magnets with a speed commensurate to that of its revolution.

8. The combination of a shaft, an armaturecore, and internal field-magnets secured to and carried by said shaft, a stationary external field-magnet, and coils 011 said armaturecore and internal field-magnets in which the resistance of the armature-coils is very low and the resistance of the internal field-coils is relatively very high.

9. The combination of a shaft, an armaturecore, internal field-magnets secured to and carried'by said shaft, a stationary external field-magnet, coils on said armature-core in which the resistance is very low, coils 011 the internal field-magnets in which the resistance is relatively high, and a commutator having its sections connected each to one of the high and one of the low resistance coils.

10. In a dynamo-electric machine or motor, the combination of a shaft, non-magnetic frames secured to said shaft, an armaturecore and a supplemental internal field-core, both secured to and between said non-magnetic frames so as to be rigid with respect to each other, and coils upon each of said cores.

11. The combination of an armature and internal field-magnets built as one structure and rotating at the same speed, in combination with a supporting-shaft, two external field-magnets of the horseshoe type, having their poles arranged toward each other, nonmagnetic standards at each end of the mastandards and in fixed relation to the armature and internal field-magnets.

12. The combination of an armature and internal field fixed thereto and having their coils arranged in parallel, and an external field having a coil also arranged as a shunt with respect to the armature-coils.

13. The combination of an armature and internal field fixed thereto and having their coils arranged in parallel, an external field having a coil. also arranged as a shunt with respect to the armature-coils, and a second coil connected in series with the armature.

14. The combination of an armature and internal field fixed thereto and having their coils connected in parallel and the internal field-coil arranged as a short shunt with respect to the armature, an external field having a coil connected in series with the armature, and a second coil connected as a long shunt around the armature and series fieldcoil.

15. In a dynamo or motor, the field-magnets having two coils, with a third coil of magnetic metal wound upon the field and interposed between said field-coils.

1b. In a dynamo or motor, the field-magnets having two coils, with a third .coil of magnetic metal wound upon the field and interposed between said field-coils, and a circuit for passing part of the current which energizes the machine through said coil of magnetic metal.

17. In a dynamo or motor, the field-magnets having two coils, with a third coil of magnetic metal wound upon the field and interposed between said field-coils, a circuit for passing part of the current which energizes the machine through said coil of magnetic metal, and a switch to out said coil out of circuit.

18. In a dynamo or motor, 'a field-magnet formed of a series of U-shaped sections separated to form air-spaces between them, in combination with an armature and its shaft, end standards having bearings for said armature-shaft, and bolts for clamping IIO said sections together and to the end standards.

19. In a dynamo or tnotor, a tieldrmagnet formed of a series of U-shaped sections separated by distance-pieces formed integral with them to form air-spaces between. them, in combination with an armature and its shaft, end standards havingbearings [or said armature-shaft, and bolts for clamping said sect-ions together and to the end standards.

20. A field-magnet consisting of the heavy cast sections A A having the distancepieces a a, forming ventilating-spaces C, in combination with the bolts 13, passing through the polar extensions to unite said sections together.

21. In a dynamo or motor, the combination of two oppositely-arranged horseshoe-shaped magnets brought close together in the central lines of the poles of the machine, standards at each end, and long clamping-bolts to unite the magnets rigidly together and to the standards.

22. In a dynamo or motor, the combination of two oppositely-arranged horseshoe-shaped magnets formed ot a series of heavy sections and having their polar extensions brought close together in the central lines of the poles of the machine, standards of nonmagnetic metal at each end, and long clamping bolts to unite the magnet-sections rigid together and to the standards.

In a dynamo or motor, the combination of two oppositely-arranged horseshoe-shaped magnets brought close together in the central lines of the poles of the machine, standards at each end, long clamping-bolts to unite the magnets rigidly together and to the standards, an armature, and an armature-shaft journaled in said standards.

24. The combination of two oppositely-ar- *anged horseshoe-shaped magnets having integral polar extensions made long and brought together in a line corresponding to the center of the two poles of the machine and a frame or frames for uniting said field-magnets together to form the armature-space.

25. The combination of two horseshoeshaped field-magnets having integral polar extensions and brought together to form continuous or practically-continuous north and south poles for the armature, end frames or standards having bearings for the armatureshaft, long bolts which extend through the four polar extensions and unite the standards thereto into a rigid structure, an armature rotatin within the space bounded by the polar extensions, and an armatureshat't journaled in the standards.

26. The combination of two horseshoe shaped field-magnets formed of cast sections divided in the direction of their length and having their polar extensions made integral and brought together to form continuous or practically continuous north and south poles for the armature, end frames or standards having bearings for the armature-shaft, long bolts which extend throughthe sections'of the four polar extensions and unite the standards thereto into a rigid structure, an armature rotating within the space bounded by thepolar extensions, and an armature-shaft journaled in the standards.

27. The combination of two oppositely-arranged horscshoe-shaped field-magnets without yoke-joints and formed in sections of ductile magnetizable metal and having their polar extensions made integral and brought together in the central lines of the poles of the completed machine, thereby forming a substantially continuous magnetic band around the armature, with two joints diametrically opposite and in line with the centers of the poles of the machine.

28. A field-magnet section formed ofhorseshoe shape and of magnetizable metal, with the separating projections a a and the curved face A to form the armature-space.

29. An integral field-magnet section formed of horseshoe shape and ot' malleable iron, with the separating projections a a and the curved face A to form the armature-space.

30. The combination of two horseshoeshaped field-magnets formed in sections of malleable iron and uniting to form the armaturespace, two end standards of non-magnetic material, bolts for holding the sections of the field-magnets and standards rigidly together, and an armature and its shaft journaled in the stamlanls.

. The field-magnets A A, made horseshoe shape and formed of sections A A having air-spaces C 0 between them and having their' polar ends brought together, as set cut, end standards, D, of non-magnetic material, having bearings, bolts B, extending through the sections A A and standards to unite them all into a rigid structure, an armature, and its shaft journaled in the standard-ln arings.

32. The combination of an armature and an internal field-magnet with a wrapping of magnetic metal between the armature and field windings.

In testimony of which invention I hereunto set 'my hand.

RUDOLPH M. HUNTER.

Witnesses:

E. M. BREexIxnEEn RICHD. S. CHILD, Jr.

IIO 

